Switch



R. B. BELL SWITCH Filed Sept. 27, 1947 Feb. 3, 1953 `Patented Feb. 3,1953 SWITCH Rupert B. Bell, Ann Arbor, Mich., assignor to King-SeeleyCorporation, Ann Arbor, Mich., a

corporation of Michigan Application September 27, 1947, Serial No.776,497

6 Claims. (Cl. 2011-153) 1 The present invention relates to anelectrical switch of the type particularly adapted for operation by amechanical means, such as the moving part of a machine, a system oflevers or a 2 housing section includes a contact receiving recess 'Iformed'in the face 8 which mates with the corresponding face of theother section. The recess 'I is connected by means of a pair of slots 9and mechanical timing device. 5 IU to the rear face I I of the section.The recess It is the'general object of the present invention 'I is alsoconnected by a semicircular slot I2 to the to provide a switch of thetype mentioned charfront face I3 of the section, and the bottom ofacterzed by its extreme simplicity, low cost and the recess is formedwith three aligned spaced ease of assembly grooves or recesses I4, I5and I 6, which, as here- Other objects and advantages of the invention winafter pointed out, serve to locate and support will become apparentfrom the following specithe contact elements Within the housing sectionscation, the accompanying drawing and the apon assembly. The housingsections may be pended claims. secured together in any suitable manner,such as In the drawing: by a pair of bolts, which bolts are adapted topass Figure 1 is a rear elevation of the switch, show- 15 throughopenings Il and I8 formed therein. It ing the same mounted on asupporting panel; will be noted that the openings Il are co'unter Figure2 is a sectional view taken on the line sunkto receive a raised annularboss I9 formed 2-2 of Figure 1; on the face 8 of each section around theopening Figure 3 is a sectional view taken on the line I3 therein. As aresult of this construction, the 3-3 of Figure 1; i i o engagement ofthebosses I9 within the counter- Figure 4 is an exploded view, showingin persunk portions of the openings I'I prevents relative spective allof the parts forming the switch; and displacement between the housingsections I and Figure 5 is a fragmentary section taken on the 2 in aplane Parallel t0 the mating faces 8 and ,line 5-5 of Figure 3. ieliminates the necessity of having a close nt be- The principles of theinvention are shown in 5 tWeen the Openings l'l and I8 and the bolts 20the drawing as incorporated in a normally open which secure the housingsections together and single pole switch of the type employing two pairs't0 any Suitable Supporting member, Such as the of mating contacts whichare connected in paralplate 2|. A lel and which successively engage whenthe switch The StatiOnaIy contact element 3 comprises a is closed andsuccessively disengage in the reverse 30 single at plate 22 llaVing apail 0f ccntact eleorder when the switch is opened, thus insuring ments23 and 24 xedly secured thereto. The that any arcing at the contactswill always occur l-Dlate 22 is formed Of any electrically conductive atone pair of engaging contacts and` leaving the material, Such es copper01' brass, and is provided other pair of contacts free of any impairmentwith two pairs of Oppositeiy extending ears 25 which would otherwiseadversely affect their cur- 25 and 26. The Contact elements 23 and 24are rent carrying capacity. It will be appreciated, secured to the plateby riveting, and the contact however, that the principles of theinvention are 23, Which is, in itself, in the form 0f a rivet.applicable to other forms of switch mechanisms. Serves t0 secure aterminal 2l t0 the plate, in the such as normally closed switches orswitches manner best ShOWn in Figure 2. which incorporate only one pairof engageable 40 The mOVable ccntact element 4 comprises a contacts.suporting plate 28, which is generally rectangu- T As shown in thedrawing, the complete switch lar in form and of the same dimensions asthe assembly comprises a pair of mating housing sec- DOItiOn 0f plate 22Which includes the ears 26 tions, indicated generally at I and 2, withinwhich and contact 24. VA spring bronze or other suitable are supported astationary contact element 3 and 45 electrically conductive flexiblecontact arm 29 a movable contact element Il. The movable conand aterminal 30 are fixed to the plate 28 by tact is actuated by means of abutton 5, which means of a double ended rivet 3|, the arm 29 andprojects through a suitable opening in the housthe plate 28 being heldin spaced relation by a ing and is actuated by one end of a reverselybent head 32 located intermediate the ends of the rivet. leaf spring 6,en The arm 29 has riveted thereto a pair of contact An important featureof the invention resides elements 33 and 34, the formel' being locatedinin the fact that the housing sections I and 2 are termediate the endsof the arm and the latter identical to each other, with the result thatboth adjacent the outer extremity thereof, maybe formed on the same setof dies from any A further important feature of the invention `suitablematerial, such asamolded plastic. Each 5.5-resides in the fact that thesymmetrically arranged recesses I4 and I5 in the identical housingsections I and 2 may, due to the construction and arrangement of thecontact elements 3 and serve to locate and support either one ci thecontact elements interchangeably. Thus, if the parts are assembled whilethey are in the relative positions indicated in the exploded View ofFigure 4, the ends oi plate 2S are ntted within the notch I4 in sectionI and the notch I@ in section 2, while the ears 26 on the contactelement 3 are tted in the notch I6 of section I and the notch I4 ofsection 2, in the manner best shown in Figures 2 and 3. However, ifdesired, the position of the contact elements 3 and il may be reversedwithout in any lway changing the construction or mode of operation ofthe final assembly. In that case, the ends of the plate 28 are ttedwithin the recess IS in housing section I and I4 in housing section 2,`while the ears 26 are iitted within the recess Il?. of section I and ISof section 2. In either case, the ears 25 of section 3 nt within therecesses I of both housing sections and in both cases the terminals 27and 3d will lie in the openings formed by the mating slots 9 and Iii.The fact that the contact elements may be interchangeably positionedwithin the housing greatly facilitates assembly, since the parts cannotbe assembled in an improper relationship and it is unnecessary tomanipulate the housing sections to one of the two possible positions inorder to achieve a successful assembly.

When the switch is assembled, the button E, which is an entirely loosepiece, is inserted in position with its projecting end extending throughthe opening formed by the mating notches I2. The external operatingspring l'6 has a U-shaped end portion 35, which is adapted to 'fitwithin an L-shaped recess 33 which is formed in the face 8 of eachhousing section and which opens to the front face I3 of each section.The width of the spring 3 is almost twice the depth of the recess 36formed in each section, with the result that on assembly the spring lieson opposite sides of the plane containing the mating faces Ii of thehousing sections. The U-shaped end of the spring loosely its within theL-shaped recess 36 and forms, in effect, a pivotal mounting for the endof the spring. The connection thus aiforded between the spring and thehousing cannot be disconnected without separating the housing sections.The opposite end of the spring is provided with a U-shaped sectionhaving a terminal portion 3l which engages the operating button 5.

It will be understood that the spring 6 may be omitted if desired, andthe switch operated by direct actuation of the button 5. However, sincein mechanically operated switches of the type here involved it isfrequently diiiicult to eliminate overtravel of the mechanical devicewhich operates the switch, it is desirable to'prcvide, in connectionwith the switch mechanism, means to permit such overtravel withoutdamage to the switch, itself. For that purpose, the spring 6 isprovided. Thus, on application of a switch actuating force to the springin the direction indicated by the arrow in Figure 2, the switch contactswill engage and thereafter the spring may further distort to permitovertravel, if any, in the operating mechanism which exerts the force.It will be observed that since the switch closing force is applied bybutton 5 to the central portion of the iiexible arm 29, the contactelement 34 will engage its mating contact element 24 before engagementbetween the contacts 33 and 23 occurs. Conversely, as the switch isopened, contacts 33 and 23 will disengage before disengagement ofcontacts 34 and 24 occurs. Consequently, all of the arcing will occur atthe contacts 24 and 34. This will leave the surfaces of the contacts 23and 33 unpitted and thus prevent impairment 0f their current carryingcapacity. The contacts 24 and 34 are provided solely for the purpose oftaking the arcing on closure and opening of the switch in the mannerdescribed above, and are otherwise unnecessary since all of the currentmay be carried by the contacts 23 and 33.

It will be noted that since the two housing sections I and 2 areidentical, there are two sets of recesses 36 in each housing. Thispermits mounting of the spring 6 at either end of the housing withoutchanging the mode of operation or characteristics of the device. Theexternal mounting of the leaf spring 6 is particularly advantageous inthat it permits direct observation and adjustment of the amount of-overtravel provided thereby. As a result, damage to the switchmechanism due to excessive overtravel in the operating mechanism iseasily'avoided.

A further feature of the invention resides in the detailed constructionof the notches or recesses I4 and I6. Asbest shown in Figure 5, thenotch It is ofgreater width than the ears .26 on plate 22. However, oneside of the notch is formed with a centrally located projection '31while'the opposite side is provided at each end with a pair ofprojections 38. The arrangement is such that whenthe-ears 23 are forcedintothe notch or recess, the projections 31 and 38 bend the ears in themanner best shown in Figure 5. For this purpose the outer ends of theprojections are slightly rounded or inclined in order to lbend the earsby a camming action as theyare forced into the recess.

It will be understoodk that the notch or recess I4 is constructed in thesame manner as'notch Iii and similarly coacts with the ends of plate28.- Also plates 28 and'22 are of the same thickness with the resultthat plate .28 maybe fitted in either notch and the ears on plate 22 inthe other.

Two important-advantages flow from the'above .described notch or recessconstruction. In the iirst place, the projections 3l and .38 positivelygrip the ears28 and the ends of plate 28 and thus Yhold the associatedcontacts in a fixed position within the housing independent ofvariations in thethickness of the plates 22 and 28 and the width of thenotch which result from normal manufacturing tolerances. Secondly, thefriction induced by the ltendency of the bent ears and bent endsv ofplate 23 to return to a nat condition holds the two housing sectionstogether suiiiciently to permit normal handling of the assembled switchprior to insertion of the permanent fastening means (rivets or bolts)through lopenings I'I and I8.

While, as shown in the drawings and described above, the notches I4, I5and I6 are recessed'below the bottom surface of the recess I, it will beapparent that this is not necessary since the surfaces which engage theplates 22 and 28 and hold them in position may be formed on .projectionsextending above the general level of the bottom of recess 'I withoutchanging the principle or-advantages of the invention.

While only one form of the invention is shown and described herein, itwill be apparent that variations in the details of construction may beindulged in without departing from the spirit of the invention or thescope of the appended claims.

What is claimed is:

1. A. switch, comprising a housing formed of two identical sectionshaving mating recesses forming an internal chamber for the reception ofrelatively movable switch contacts, said sections h-aving mating slotsthrough the side walls of said recesses adapted to receive switchterminals, a pair of switch contact elements each having a supportingportion and a pair cf equally spaced contact portions and a terminal,the contact portions on one of said velements being xed to a exiblestrip one end of which is fixed to the supporting portion of saidelement, the supporting and contact portions being located within saidchamber and the terminal portions lying in said mating slots, thecontact portions on the iiexible strip being so positioned that onfiexure oi said strip in one direction the contacts on one elementengage the contacts on the other in succession and on ilexure in theopposite direction said contacts disengage in the reverse order, each ofsaid housing sections having surfaces formed to engage the supportingportion of each of said contact elements and support the elements inproper relative position, each housing section being symmetrical withrespect to a central plane extending transversely thereof so that saidcontact elements may be reversed without altering the relative positionsof the contact portions or said elements, and means projecting from iehousing for flexing said strip.

2. A switch, comprising a housing formed of two identical sectionshaving mating recesses forming an internal chamber for the reception ofrelatively movable switch contacts, said sections having mating slotsthrough the side walls or" said recesses adapted to receive switchterminals, a pair of switch contact elements each having a supportingportion and a contact portion and a terminal, the contact portion on oneof said contact elements being fixed to a exible strip, one end of whichis fixed to the supporting portion of said one of said elements, thesupporting and contact portions being located within said chamber andthe terminal portions lying in said mating slots, the contact portion onthe flexible Strip being so positioned that on flexure of said strip inone direction the contact on one element engages the contact on theother, each of said housing sections having surfaces formed to engagethe supporting portion of each of said contact element-s and support theelements in proper relative position, each housing section beingsymmetrical with respect to a central plane extending transverselythereof so that said contact elements may be reversed without alteringthe relative positions of the contact portions of said elements, andmeans projecting from the housing for flexing said strip in said onedirection.

3. A switch, comprising a housing formed of two identical sectionshaving mating recesses forming an internal chamber for the reception ofrelatively movable switch contacts, said sections having mating slotsthrough the sidewalls of said recesses adapted to receive switchterminals, a pair of unitary switch contact elements formed ofelectricity conducting material and each hav ing a supporting portionand a contact portion and a terminal, the supporting and contactportions being located within said chamber and the terminal portionslying in said mating slots, each of said housing sections havingsurfaces formed to engage the supporting portion of each of said contactelements to hold said supporting portions in xed relation to saidhousing and support the elements in proper relative position, one ofsaid elements being deformable to move the contact portion thereof intoengagement with the contact portion of the other of said elements andmeans projecting from the housing :for so deforming said one of saidelements.

4. A switch as dened in claim 3 wherein the cont-act portion andterminal of each contact element is permanently fixed to the supportingportion thereof.

5. A switch comprising a housing formed of a pair of mating sectionshaving recesses which combine to form an internal chamber, and switchmechanism disposed within said chamber mounted on said housing andincluding a pair of sheet metal mounting plates within said chamber andextending in planes transverse to the plane of juncture of saidsections, and a pair of relatively movable switch contacts carriedrespectively on said plates, each of said sections having surfacesformed in said recesses which distort said plates from their freecondition and frictionally engage said mounting plates at opposite sidesthereof to hold said plates in a distorted condition.

6. A switch as defined in claim 5, wherein said mounting plates havelaterally extending portions received in said recesses and engaged anddistorted by said surfaces.

RUPERT B. HELL.

REFERENCES CITED The following references are of record in the le ofthis patent:

UNITED STATES PATENTS Number Name Date 1,830,084 Bjorndal 1 Nov. 3, 19311,981,064 Norviel Nov. 2&0, 1934 1,987,025 Peterson Jan. i8, 19352,053,373 Money Sept. 8, 1936 2,304,764 McAllister Dec. 8, 19422,332,911 Hausler Oct. 26, 1943 2,341,931 Lloyd Feb. 1.5, 1944 2,385,165Sears Sept. 18, 1945 2,398,996 Benander Apr. 23, 1946 2,419,072 HallApr. 1.5, 1947 2,456,548 Weiner et al Dec. 14, 1948 2,459,427 HumpageJan. 18, 1949 2,497,484 Wood Feb. 14, 1950 2,507,381 Morse May 19, 1950OTHER REFERENCES Ser. No. 322,436, Leifer (A. P. CL), published May 18.1943.

